Automatic outlet box making machine



Oct. 12, 1943. R. M. WALKER l-:TAL 2,331,525

AUTOMATIC OUTLET BOX MAKING MACHINE Filed Nov. 6, 1941 12 Shee'c-Sheel; 1

Gio/Q62' A ALEM MD5/ej VENTORS.

BY /Z J A TTORNEYJ.

Oct. l2, 1943.

Nl TNESB.'

R. M. WALKER ET AL 2,331,525

AUTOMATIC OUTLET-BOX MAKING MACHINE 12 sheets-sheet 2 Filed Nov. 6, 1941 ATTORNEYS? Oct. 12, 1943. n R, M, WALKER ETAL 2,331,525

AUTOMATIC OUTLET BOX MAKING MACHINE Filed Nov. 6, 1941 12 Sheets-Sheet 3 FIG Oct. 12, 1943. n M. WALKER Erm. 1 2,331,525

AUTOMATIC OUTLET BOX MAKING MACHINE med Nw. e, 1941 12 sheets-sheet 4 HHM NIN BY ZEV Nl Tis/ESS.'

I "j" y ATTQRJVHS.

OCI. 12, 1943'. R, M, WALKER ETAL 2,331,525

AUTOMATIC OUTLET BOX MAKING MACHINE G50/F65 ,afm/vage; INVENTORS.

A ATTORNEYS Oct. 12, 1943. R. M. WALKER Erm. 2,331,525

-AUTOMATIC OUTLET BOX MAKING' MACHINE y 12 Sheets-Shes?I 7 Nm. s

llllllemvlhhn Alllll dw .v

Filed Nov. 6, 1941 O O O O 0 G G O O O O O O O O O .NNGHE QV w Nw s bv S ,.A. m n el L M W. M W M .a .n N /R O n ,VA

Oct. l2, 1943,. R. M. WALKER ETAL 2,331,525

AUTOMATIC OUTLET BOX MAKING' MACHINE Filed Nov. e, 1941 12 sheets-sheet s BY o# nain ATroR/ VEY Oct. l2, 1943. R. M. WALKER l-:TAL 2,331,525 y AUTOMATIC vOUTLET BOX MAKING MACHINE v I Filed Nov. 6, 1941 l2 Sheets-Sheet 9 WITNESS.'

A TTORNEYS.

Oct. 12, 1943. R. M. WALKER Erm. 2,331,525

' AUTOMATIC QUTLET BOX MAKING MACHINE Filed Nov. e, 1941 12 sheets-sheet 1o` CoM/DANY 0F GEORG/4, Ex'cara/P A/vo GEOeGE R ALExA/voe/ INV ENTORS.

Oct. 12, 1943. R. M.- WALKER ETAL l 2,331,525

AUTOMATIC OUTLET BOX MAKING MACHINE Filed NOV. 6, 1941 12 Sheets-Sheet 11 INVENTORS.

. ATTORNEYS.

Oct. 12, 1943. R. M. WALKER. ETAL 2,331,525

I AUTOMATIC OUTLET BOX MAKING MACHINE Filed Nov. 6, 1941 12 Sheets-Sheet 12 Ilz-@..

i. Il. /q l@ INVENTORS BY maw Nif/V535: l

A TTORNEYS.

Patented Oct. l2, 1943 -I AUTOMATIC OUTLET BOX MAKING MACHINE. f

Ralph M. Walker, deceased, late of Atlanta, Ga., by Mabel B. Walker and Trust Company of Georgia, executors, Atlanta, LGa., and George I. Alexander, Miami,l Fla., assignors to Walker Electrical Company,Atlanta, Ga.; a corporation of Georgia Application November 6, 1941, Serial VNo. 418,026

9 Claims.

This invention relates to improvements in automatic machines for successively performing operations upon pieces of Work, and more specifically the invention relates to an automatic `machine for making outlet, junction, andy-other l metal electrical boxes of the type having knockout openingstherein and which are used in electrical installations. ,l

The primary object of thisvinvention resides in an automatic machine for the making of outlet boxes which will `reducethe cost of labor and expedite thermanufacture o f outlet boxes in comparison with the conventional methods and apparatus heretofore employed for such purpose.

Another feature of the invention is to provide an automatic combined machine for, rst; trimming the edges oi a drawn metal outlet box and simultaneously forming the cover attaching ears; second, punching the knockouts in the several side walls thereof, which knockouts are pushed beyond the plane of thev side walls; third, replacing the punched knockouts in the several side walls; fourth, bending the opposed cover attaching ears at right angle to the side walls;

fifth, tapping the attaching ears; and, sixth,"l

grinding the burrs on the free edges of the side walls and -thereby completing the outlet box.'

A further feature of the invention is the provision of an automatic machine in which the above mentioned operations are simultaneously performed on a plurality oi' outlet boxes as they successively pass from lone operating work station to anothenfthus eliminating the individual manual operations and machinery now employed-H35 in the manufacture of outlet boxes.

With these andA other objects `in view, the invention resides in the novel combination and arrangement cf mechanisms hereinafter fully described and illustrated in detail in the accompanying drawings, in which,

Figure l is a plan view of the metal blank disk from which an outlet box i sformed.

Figure 2 is an edgeelevation thereof.`

Figure 3 is a top plan view-of a square shape4` Figure `8 vis ra verticalsectional viewonfthe line 3 8 of Figure 7. l

Figure 9 is a plan view of the box illustrating the four side wall knockouts punched therein and disposed on a plane inwardly of the side Walls.'

Figure lo is a vertical sectionalview on the line Ill-Ii) of Figure 9.

Figure 11 is a top plan View illustrating the side wall knockouts replaced.

Figure12 is a vertical sectional view on the Figure 13 is a plan View of the box with the attaching ears `bent inwardly .at right angle to theside walls.

VFigure 14 is` a Vvertical sectional view on the line Id--I of Figure 13. v

Figure 15 is an enlargedvertical fragmentary sectional'view illustrating4 the openings in the attaching ears as'having been thread tapped. p

`Figure 16 is a perspectiveview of the outlet box with the burrededgesground off and in iinished condition' for use.

AFigure 17 is a' iront elevational view of the outlet box making machine with the ram in raised position. i j

Figure 18 is'atop plan view of the machine.

Figure 19 is a right end elevational View of the `machine.

4on the line 2li-28 of Figure 17.

Figure 21 is an enlarged vertical transverse sectional view on the line 2l-2I of Figure 17 illustratingthe position of the parts when the ram is in lowered position in full lines, the ram being shown in raised position in dotted lines.

Figure 22 is an enlarged fragmentary front elevational view.

' Figure 23 is a fragmentary horizontal sectional view on the line 23-23 of Figure 22.

Figure 24 is an `enlarged. fragmentary top plan View of the machine. Y Y

Figure 25 is a fragmentary vertical longitudinal sectional view onl theline iid-25 of Figure 24.

Figure 26v is an end elevational view of the box carrier mechanism looking at the left'end and-illustrating the position of thesame when picking up a box at the feed chute-certain parts being shownin section. i y i Figure 27 is a View similar to Figure 26, vbut showing the box carrier mechanism in position to present the boxes carried thereby to the respective work stations. -i

Figure 28 is a right end elevational view of the box carrier mechanism, the parts being shown in box'pick up and box stripping position.

Figure 29 is an enlarged fragmentary vertical sectional view on the line 29-29 of Figure 24.

Figure 30 is an enlarged vertical transverse sectional view on the line 30-30 of Figure 24.

Figure 31 is a fragmentary vertical sectional view on the line 3 -SI vof Figure 30.

Figure 32 is a detail vertical sectional View on the line 32-32 of Figure 3l.

Figure 33 is a detail top plan View with parts broken away of two adjacent trimming dies of a knockout punch.

Figure 34 is an enlarged detail vertical sectional view through one of the knockout dies.

Figure 35 is an enlarged detail vertical sectional view through one of the return knockout dies.

Figure is an enlarged detail vertical sectional view through one of the ear bending dies.

Figure 37 is an enlarged detail Vertical transverse sectional view taken substantially on the line `Zil--S'I of Figure 17, the box carrier being shown in a position presenting a box to the tap mechanism.

Figure 38 is a diagrammatic wiring diagram of the electrical control ior actuation of the thread tapping device.

Figure 39 is a diagrammatic wiring Adiagram of the clutch control' means.

In Figures 1 and 2 of the drawings, there is illustrated a round thin blank of "metal A winch is placed in a drawing machine and `drawn into the shape shown in Figures 3 and 4 to provide a box structure B consisting of a rectangular bottom wall C, four side walls D having irregular shaped edges E from portions of which the cover attaching ears are formed vby cutting and bending operations performed by the automatic machine IU to be hereinafter 'fully described. Jft'er the blank A has been drawn to the shape 'shown in Figs. 3 and4, the metal box structure is 'pla'ced into a 'punching machinev to punch one or more knockouts F in the bottom Wall "C, and spaced opposed nail openings G, four o'whic'ha're shown as being equidis'tantly spaced from the center of the bottom wall, although additional -nail openings G may be provided. The `operations s'o liar described are performed by m'eans other than by the automatic machine I and the box B is inserted into the machine ID to perform the remaining operations necessary to complete the outlet box to finished form shown in Figure 1S.

The metal box B is inserted into the automatic machine I0 in the form shown in Figures 5 and 6, use being made of a pair of opposed nail openings G to support the box in vits travel through the machine. The rst operation of the machine upon the metal box is to cut away the irregular edges E and to form upstanding ears H--H respectively on opposed side WallsI of the box and to punch holes J therein as illustrated in Figures 7 and 8. The next operation is to successively punch a knockout K in each of the rfour side walls of the `box as shown in Figures 9 and l0, which operation disposes the knockouts K inward of the plane of the respective side walls. The machine successively `replaces theknockouts K to the position shown in- Figures 11 and l2, immediately after the knockout punching operations. The next operation Vis tobend the ears H--H inwardly as shown in Figures 13- and 14, followed by a screw threadtapping operation to thread the4 holes J l (Figure: 15). The next and final work operation of the machine is to subject the free edges of thev box to a grinding 'operation to remove therefrom any burrs which might be present due to the previous trim cutting operations, whereupon the outlet box B assumes the finished appearance as illustrated in Figure 16.

The automatic box making machine ID includes a U-shaped frame II of sturdy construction having a horizontal base I2, right and left upstanding end pedestals I3 and Ill respectively which have set back 4portions to provide opposed horizontal seats l 5-15 which support the ends of a horizontal bed-plate I6, and which bed-plate is fixedly .secured to the seats in any conventional ina-nner. 'The tops of the pedestals I3 and I4 are provided with alined bearings Il--I I in which the ends of a ca'm shaft I3 are journaled. Fixed to the shaft I8 at suitably spaced intervals therealong are double cam members i9, three of which have been shown in Figure 17. Each cam member i-S comprises a ram lowering cam 20 and a ram lifting cam 2|, the said cams 2U and 2I being `connected vby a hub 22. The cams 23 constantly `engage rollers y23 rotatably mounted in bearings 24 extending upwardly from a ram 25, the ends of the ram `being slidably mounted for vertical movement in `gibs 26 provided on 'the inner sides of the pedestals I3 and M. Pairs of transversely alined connecting rods '2l rise upwardly from the ram 25 and have their upper ends lconnected toa head plate 28. The pairs of connecting rods 21 -are suitably spaced a lengthwise `direction and slide through a horizontal guide plate '28 which 'is supported at its ends upon the pede'stals I3 and M. 'The plate 23' is slotted as at `29 fadjacent lthe cam members I9 toaccommodate the 'same and the rollers 23. Rollers -2 I are mounted in bearings 2li depending from the head plate 23 and respectivelyen'gage the cams 2l. From the description thus far it will be vunderstood 'that the ram 25 is in reality supported by the cani rnem'lfiers I 9, therefore any rotation imparted 'to the cam 'shaft 118 will impart a smooth uniform vertical reciprocating movement to the ram 25. The means for imparting reciprocating movement to 'the 'ram 25 will now be described although tiine intervals between each complete 'cycle of reciprocation occurs for reasons to Abe hereinafter 'appreciated and vsuitable control means-for that purpose is provided.

The right end `of the cam shaft I8 extends beyond the pedestal I4 and has a ily-wheel gear 36 freely rotatable'thereon, the same having an inwardly extending recessed hub 3l. The side Wall of the recess of the hub 3I is provided with a bevel friction clutch surface 32 which constitutes a female lclutch element'which is engageable with `a male beveled friction clutch 'element slidably splinedl upon the shaftv `I3 as at A-n 'expansion spring -35 is Yinterposed Vbetween the male clutch element-33A and a 4collar 36 fixed to the shaft I'I and `enclosed in the recessed hub. The spring 35v tends to normally slide `the -male clutch element away from the beveled surface 32 of the female clutch element, however, suitable electrically controlled means is provided to cause V.the ima-le clutch element to drivingly engage the female clutch element in timed relation to the working parts of the machine. Such control means includes va kflanged collar `3l iixed to the male clutch element 33 with which the yoke .portion `of a verticallydisposed levcr33 is operatively connected, the yoke portion of :the lever having Abearing rollers 39 which engage the -flanges' of the flanged collar to prevent binding between the lever and the collar during relative movement therebetween. The upper end of the lever 38 ispivoted as at 40 tothe platform 4l mounted on the top of the adjacent bearing Il, while'the lower end of the lever is connected by a pin and slot connection 42 to the outer end of the sliding armature 43 of an electric solenoid 44, the latter being xedly mounted on the pedestal I4. An electric motor 45 is mounted on the platform 4l and its armature shaft 45 has a pinion 4! which constantly meshes with the ily-Wheel gear 3D. Thus, by intermittently energizing the solenoid 44, the lever 38 is actuated to effect engagement and permit the disengagement of the clutch elements 33 and 32 to control intermittent rotation to the cam shaft i8 when the motor.45 is turned on to cause pinion 41 to continuously rotate the fly wheel gear 35.

Disposed beneath the ram 25 is a vertical horn-die carrier plate 48 which extends from the right end of the machine to a point short of the left end thereof and which has its ends slidably mounted in guide gibs 49 to facilitate up and down sliding movement in timed relation with the downward and upward `movements respectively of the ram 25. When the plate 45 is at the limit of its downward movement its bottom side restsupon the front bevel face 55 of a sliding wedge plate 5l which is slidably supported by the top face of the bed plate I5. The sliding wedge plate 5l extends substantially the length of the carrier plate 48 and is guided during its sliding movement by a guide plate 52. By imparting a reciprocating sliding movement to the wedge plate 5| the same will alternately raise the carrier plate 43 and also permit the same to gradually drop by gravity to lowered position. The means for imparting reciprocating movement to the wedge plate 5I in suitably timed relation to theV reciprocation of the ram 25 will now be explained.

Mounted rearward of the wedge plate 5! and extending lengthwise of the machine is a cam shaft 53 mounted in bearings 54. The right end of the shaft 53 extends beyond the right end pedestal i4 and has a Geneva wheel 55 xed thereto, while the left end of said shaft terminates beyond the left end of the wedge plate 5l. Two actuating egg shaped cams 56 are xed to the shaft 53 and are respectively disposed beyond the ends of the wedge plate. Each cam 56 hasa cam groove 51 in the inner face thereof which follows the peripheral contour thereof and into whicha roller 58 rotatably mounted at the adjacent end of the wedge plate extends. There is a dwell spotin each cam 56 which permits the wedge plate 5I to remain stationary when the ram 25 is in down position and the horn carrier plate 48 is in a raised position as illustrated in Figure 2l for reasons to be hereinafter appreciated.

The cam shaft 53 is rotated by an intermittent drive consisting of the Geneva wheel 55 which is engaged by a Geneva pinion 59 which is fixed to a stub shaft 59 journaled in the pedestal I5 as best illustrated in Figs. 17 and 19. Fixed to the Geneva pinion is a pulley 5| about `which a driving pulley belt 62 passes. The belt 52 also passes over a pulley 63 fixed to the power takeoff shaft of a speed reducer B4 which is driven by an electric motor 65. The speed reducer and motor are supported by a bracket 53 attached to and extending outwardly from the right end of the U-shaped frame structure il. `By means of the Geneva movement, the continuous driving rotation of the speed reducer 64 is converted into an intermittent rotation for imparting a corresponding rotation to the cam shaft 53 to effect a lstep by step forward and backward movement 5 to the wedge plate 5I through the medium of the cams 55 and rollers 53. f

In view of the fact that to performfall of the y trimming of the four side edges E of thebox, to apply the knockouts K in the four side walls l thereof, to replace the knockouts K, and to bend the two ears H, the ram 25 and horn carrier plate 48 must be provided with fourteen sets vof complementary die elements, each set of die elements constituting a work station to which the l outlet box B is presented during its travel from the right loading end of the machine to the left box discharge .endthereof In addition to the trimming,` punching and bending dies for performing the above mentioned respective operations, there are two additional stations atV the left end of the machine, namely, a tapping station Y for threading the holes J in the ears H, anda grinding station Z for removing burrs from the edges of the side walls of the box, thus making sixteenwork stations in all, extending aloner the length of the machine, the rst fourteen of which rely upon the timed vertical reciprocation `of the ram 25 and horn carrier plate 48 for theil` respective operations.. To simplify the description at this point, and by referring to Figure 17 of the drawings, we have designated the four trimming die stations T1, T2, T3, and T4 reading from left to right. Next to trimming station T4 there follows four equidistantly spaced knockout stations O1, O2, O3, and O4. Following the series of successive knockout stations, are four successive return knockout stations R1, R2, R3, and R4. To the left of return knockout station R4 aretwo successive ear bending stations S1 and S2. The specic complementary die elements performing the work attributed thereto will be set forth hereinafter, as will the tapping device located at the tapping station Y and the grinder located at the grinding stationvZ. All of the.

stations are equidistantly spaced from the right end trimming station T1 to the ear bending station S2, for the reason that the box carrier mechanism is intermittently operated and moves a box the same distance on each actuation thereof, which distance is equal to that between the stations T1 to S2.

Whereas the specific construction of the trimming, punching, and bending dies at the various work stations may be of various specific constructions, the lower die element carried by the carrier plate 48 of each die must be in the shape of a horn so as to enter the box when it is presented to the die station. Such shape of horn die element is illustrated in. Figure 21 and constitutes the female horn die element 6l of one of the trimming dies located at trimming stations T1, T2, T3, and T4. The horn die element 5l is substantially inverted L shape in cross section, as are the lower die elements at the knock-out stations, return 65 knockout stations, and ear bending stations. The

horizontal portion of the die element 6'! rests upon l at the various work stations are removably se,-

gear |69 has constant mesh with a pinion gear |||J mounted on the armature shaft of an electric motor supported upon a platform ||2 extending from a fixed upstanding wall ||3.

Having described the various work stations extending along the length of the machine H) and their resp-ective functions, we shall now describe the novel box carrier mechanism designated in its entirety by the numeral H4, which successively presents a box B to the work stations'l.1 to Z, however, after sixteen boxes or more have been fed to the box carrier mechanism, there will be boxes simultaneously presented to ail sixteen work stations, the boxes being moved along one station at a time whereby a steady feed of boxes to the box carrier mechanism will result in a continuous flow of boxes through the machine from the loading end to the discharge end thereof. The box carrier mechanism ||4 is disposed forward of the work stations and extends beyond the ends of the row of work stations. The carrier mechanism has an approximate thirty degree movement from a forwardly inclined box loading position as shown in Figure 26 to a vertical position (Figure 27), to present the boxes to the respective work stations relative to the horns of the trimming dies, knockout dies, return knockout dies, and ear bending dies. During approximately the first twenty degree movement of the carrier mechanism to upright position, the same moves the boxes the distance between adjacent stations, thus. the travel of fthe box carriers is intermittent and in timed relation to the actuation of the ram 25 and'horn carrier plate 4t.

The box carrier mechanism H4 includes a base plate |55 extending substantially the length of the machine and which has its rear portion pivoted at H6 to an upstanding bearing wall |I`| which rises from the bed plate I5. Extending from the top face of the base plate I l and along the length thereof at approximately sixty degree angle relative thereto is a box guide plate Nil. Depending from the base plate ||5 adjacent the ends thereof are pairs of spaced alined ears IES to which the upper ends of actuating rods |213 are connected by pin and slot connections |2l. The rods |20 freely slide in bearings |22 provided in the bed plate |6 and their lower ends are provided with forks |23 which carry rollers |2ll on their inner sides which extend into the cam grooves |25 provided in opposite sides of the heart shapedv cams |26 fixed to a cam shaft |27 journaled in bearings |28 depending from the bed-plate. I6. The right end of the shaft I'l extends through and beyond the right side of the U-shaped frame and has a Geneva wheel |29 fixed thereto which .is intermittently rotated by a Geneva pinion |30 fixed to a stub shaft ll journaled in the right end of the frame H. Also fixedto the stub shaft |3| is a pulley |32 over which a belt |33 passes, ie said belt also passing over thevdouble groove pulley 63 driven by the motor 65 through kthe speed reducer bl. Power from the motor 65 is utilized for imparting intermittent actuation to the horn die carrier i8 and to the work'carrier mechanism I4 in proper timed relation with respect to the various other'mechanisms hereinbefore and about to be described.

Supported by and secured to the upper side of the base plate H5 and extending the length thereof is a plate 34 having an upstandingbearing |35 at the right end and a bearing |36 at the left end thereof. The axes of the bearings |35 and |36 are parallel to the guide wall H8 so as to assume a vvertical position when the box carrier mechanism is in the position for presenting the boxes to the respective work stations. A stub shaft |31 is rigidly'mounted in the bearing |35 on which a sprocket wheel |33 is rotatably ymounted'. A shaft |39 is journaled in the bearing |3f5 as best seen in Figure 3l and extends down through Vbearing openings in the plates 5 and |313, the lower extending end of said shaft carrying a bevel vpinion gearv Mii. Also xed to the shaft |39 on the same plane as the sprocket wheel |36 is a companion sprocket wheel lll, and passing about the sprocket wheels |38 and it! is an endless conveyor sprocket chain |132. lThe sprocket chain |612 is intermittently actuated by imparting a predetermined rotation to the shaft |39 through the bevel pinion gear lill which has constant mesh with a larger bevel gear M3 iixed to the right end of a stub shaft IM journaled ina bearing |45 depending from the base plate H5 adjacent the leftend thereof. The left end of the stub shaft Mil has a cup rnember It fixed theretoV and which forms the driven element of a ratchet coupling Ml. Axially alinred with the left end of the shaft lsf-rl is a short drive shaft lll journaled in a bearing |49 depending from the base plate H5, the outer left` end of the shaft |48 having a gear |552 fixed thereto. The inner right end of the shaft |58 has a ratchet wheel I5! fixed thereto which extends into the cup member M6. The ratchet Ywheel |5| has ratchet recesses |52 in the periphery thereof which wedge rollers |53 into engagement with the inner peripheral wall of the cup member upon driving movement of the gear |59 in a clockwise direction of rotation to 'rotatably connect the shafts M8 and |44, while the shaft Hifi is disconnected from shaft |ll3 during counterclockwise rotation of the shaft |48 so as to remain stationary. Clockwise rotation is impartedto the gear |59 by a segmental series of gear teeth |54 provided cn the curved edge |55 of a substantially D-shaped member |56 which is xedly mounted at the left end of the bed-plate it as best illustratedin Figure 28. `When the box carrier mechanism H4 is in forwardly inclined position the gear is in mesh with the teeth and said gear is turned by rthe teeth as the lbox carrier mechanism moves to Aits upstanding position but only for a period of approximately the first twenty degrees of swinging movement thereof,` during which time the gear |553 is turned todrive the sprocket wheel MI through shafts Hi8-|44, ratchet coupling |61, gearsMS--lllil, and shaft |39, a distance sufficient to move the sprocket chain |412 an amount equal to the distance between adjacent work stations Tl to S1 along the length of the machine, so vthat when the box carrier mechanism ||4 is inits up position and the sprocket chain |42 is Astationary between its intermittent movements, outlet boxes carried by the carrier units onthe rear lead of the sprocket chainvwill present boxes tothe respective work stations. Each box carrier unit IE7-includes a stub shaft |58 having its innerfend bolted or otherwise xedly secured asr at ld to the connecting web of one of the links of the chain |42 (Figure 30), and which web is set outwardly so as not to interfere with the free passage of the links of the chain about the sprockets IM and |38. The axis of thevstub shaft |53 is right angle to the axes of the sprocket shafts |39 and |31. Rotatably mounted on each stub shaft |58 is a hub IBI having a round bore for the hub and being provided with an exterior surface which is square in cross section as at |62. as best illustrated in Figure 25. Fixed to the inner end of the hub IGI: is a gear |63 While lixed to the outer end thereof is an enlarged chuck head |64. The outer side of the chuck head |64' is flat and extending outwardly therefrom are diametrically disposed box grippers |65 which are equidistantly spaced from the axis of the head a distance equal to the spacing, between a pair of diametrically opposed openings G-G in the bottom wall of an outlet box Bi Each gripper llcomprises a pair of confronting spring jaw members |66 having their inner ends xedly secured to the chuck head |64 and their outer extending ends provided with reversely' arranged V-shaped heads |61 which are normally spaced apart with their free ends so disposed as. to enter the openings G when albox is fed to a carrier by a feeding mechanism presently to be described.

The dat: sides of the hubs lili of the box carrior units |51 ride upon` an endless supporting rail |681 which is iixedly` mounted on the base plate H5. The. supporting rail IBB comprises a front raily section |69, curved end rail sections ITIL-|10, and a rear rail section |.1| as shown in Figure 24; of the drawings, the latter constituti'ng the lower wall of an elongated guide slot i |1I provided lengthwise inthe plate H8.

As the carrier units |51 ride along the rear rail section |1| they are simultaneously turned onequarter revolution during their successive movements from work stations T1 to S1 to present the boxes to the. tour trimming, four knockouts, and tour return: knockout operations, while between ear bending stations. SI and S2 it is necessary to rotate the same one-half revolution, for the ears H-H are disposed on opposite side walls of the box. To eifect the one-quarter revolution of the box carrierunits at the proper interval, the gears |63 travel over spaced gear racks |12 provided on al mutilated rack bar |13 xedly secured to the fronty side of the upstanding panel ||8 (see Figure 25). The gear ratio between the rack |12 and gears |63 is such as to turn the carrier units one-quarter revolution during movement of the carrier units between stations 'I'r and S1. A longer gear rack |14 is provided between the ear bending stations S1 K and S2 to impart a one-half rotation to the box carrier units as they pass from station S1 to station S2.

The guide slot |1| is provided with spaced enlarged portions |15 adjacent the gear racks u |12 and |14 to permit the squared hubs |6| to clear the walls of the slot |1'| during their rotating movements, the restricted intervening portions |15 between the Walls of the slot |1| acting to guide the box carrier units and prevent accidental rotation thereof kbetween stations.

A box loading mechanism |18 is provided at the front ol the machine I adjacent the right end thereof and includes a stationary box magazine chute |11 into `which the outlet boxes in the condition shown in Figures andl are fed preparatory to their successive delivery to the box carrier units |51 by a box loaded member |13 located at the low discharge end of the chute. The box loaded member |18 comprises a body |19 having an angular tail piece |80 which is pivoted to ears |8| rising upwardly from the bedplate I6. The body is provided with an outlet box receiving seat |82 at its top onto which outlet boxes from the chute |11 are individually received. The tail piece |l is provided with a forwardly extending lug |83 which engages an adjustable stop |84 provided on the bed plate t5 when the loader member |18 is in box receiving position, as shown in Fig. 27, the forward overbalanci'ng of the loader member tending to normally causeV the same to assume a position with the seat |82; adjacent the discharge end of the chute. The upper end of the body |19 is provided with a forwardly extending closure elementy |85 which moves to a position across the discharge end of the chute when the loader' member |18; is moved to loading position relative to a box carrier unit as illustrated in Figure 26 to prevent the next box to be loaded from sliding from the chute. The loader member |19 is actuated to loading position as the base plate H5 of the; carriermechanism H4 swings downwardly by means of an adjustable, striker |85 carried by the underside of the plate |5 forcibly striking a lip |81 extending rearwardly from the body HQ. The intermittent actuation of the chain |42 successivelyV presents` the box carrier units '|51 to the box loading mechanism |16, and as the box carrier mechanism is likewise intermittently actuated to swing down and up, it actuates. the loader member |18 on its down movement` to cause the loader member to swing toward the carrier mechanism and deliver a box to an empty box carrier' unit |51, at which time the box grippers |65 enter a pair of diametrically opposed openings G. in the bottom wall of the box, afterwhich the carrier mechanism moves upwardly, the sprocket chain |42 is driven a predetermined distance to shift the loaded carner units successively to the work stations, the loadery member |18 swings down under its own weight uncovering the discharge end of the chute |11, and permitting the lowermost box in the chute to slide onto the seat |82 for subsequent delivery to the next empty box carrier unit |51 asit movesr up'to the loading mechanism |15.

As they box carrier units |51 and boxes carried thereby move about the sprocket |35, they pass 7 throughan enlarged opening |88 in the plate ifi disposed at the right end of the slot |1|, after which the hubs |6| of the carriers enter slofJ Hl and aresuccessively moved to the respective work stations from T1 to Z. After leaving the grinding station Z, the box carrier units and the boxes carried thereby pass through an enlarged opening |89 disposed at the left end of the slot |11' and thence pass about the sprocket |4| onto the front lead of the chain. At this time, the outlet boxes have been subjected to the line of work stations extending from T1 to Z and are now ready to be removed from the box carrier units |51. For this purpose we provide a box stripper device |90 at the left front end of the machine which forces the boxes from the resilient grippers |65 of the box carrier units as the finished boxes are respectively presented thereto. The box stripper device |90` is fixedly secured to the base plate H5 of the carrier mechanism ||4 and includesan upstanding wall IM integral with a supporting frame-like structure or bracket |92. The wall |9| is provided with a slot |93 extending the length thereof of a width to accor-.imodate the chuck heads |64 of the box carrier units. The inner side of the Wall |9| at opposite sides of the slot is provided with wedge camming sur-- faces |94 which extend to the entrance to the slot |93. As the boxes enter the slot |93, the bottom `wall C of the box engages the surfaces |94 and the box is gradually wedged free from the resilient jaws |66, whereupon the empty box carrier unit moves toward the right along the rail section |69 in the direction of the box loading mechanism |16 and the finished outlet box drops from the machine. A receptacle or chute may be located beneath the box'stripper ldevice I9@ to catch the outlet boxes as they are successively stripped from the box carriers.

In Figure 39 of the drawings there is illustratedl a'wiring diagrammatic view of the means for intermittently energizing the solenoid fili for effecting engagement and disengagement oi the clutch elements 32 and 33 whereby to intermittently actuate the ram 25 relative tothe intermittent up and down movements of the horn die carrier 49. The solenoid 44 is arranged in an electrical circuit |95 having a source of electrical energy. Also arranged in the circuit S is a normally open switch |96 consisting of a fixed contact |91 and a movable switch element |98, the latter being disposed in thepath of upward movementof a switch actuating arm |99 fixed to and extending rearwardly from the horn die carrier 48. As the horn die carrier nears the limit i of its upward movement by Vreason of the actuation of the. sliding wedge plate 5|, the arm |93 pushes the switchelement |98 into engagement with the contact |91 which closes the circuit |95, thusV energizing the solenoid 44 which effects a driving connection between thedriveclutch element 32 and the driven clutch element iwhereby to impart rotation of the cam shaft i8 which is necessary to effect a down and up movement to the ram which carries the upper die elements located at the respective work stations from T1 to S2.

While we have specically described the various mechanisms embodied in the automatic outlet box making machine and the operation thereof, avbrief vexplanation of the relative timing of the various mechanisms of the machine will now be set forth. It will be understood, however, that the intermittent reciprocation of A therain 25 land horn die carrier 48, are timed to operate work stations by actuation of vits operating mechanismwhich is in-timed relation to the intermittentfoperationsl of the ram and horn dievcarrier. Asthe box carrier mechanism V| I4; moves up, the sprocket drive operates to move the carrier chain |62 a distance to move the boxes to their next respective work stations. When the `machine is operating at maximum capacity, there will be outlet' boxes presented simultaneously to all the work stations from T1 to Z'whereupon each complete intermittent cycle of operation of themachine, an outlet box is fed to` a boxcarrier unit |51 of the mechanism ||4 by the loading mechanism |16, and a completed outlet box is discharged from the machine as thebox passesA the stripper device |90. y

Tracing the course of a single outlet box through the machine lil, it follows that the box loading mechanism |15 presents a box to a box carrier unit |51 when the box carrier mechanism i4 is down in the position shown in Figure 26. As the box carrier mechanism swings up, the sprocket drive is 'operated by the meshing of gear with the stationary gear segment |54 tomove the sprocket chain |42 a distance between work stations. When the box reaches the iirst work station T1 one of its side walls is subjectedv tothe trimming die 61 located at thatstation. As the sprocket chain turns on its next intermittent operation, thegear |63 of the box carrier unit engages a rack |12 and-the box carrier and box are turned `one-quarter revolution to present the next adjacent side wall to the next trimming die located-'at station 'I2 and similarly upon successive operations of the sprocket chain to the remaining trimming stations and throughout the successive stations T3 to R4 for the trimming of vthel four side walls, for punching knockouts in the four side walls, and forreturning the knockouts in the four side walls. As the box reaches station S1, its carrier' unit |51 is turned one-half revolution during its passage to station S2 by the gear lengaging the rack |14 to facilitate the successive presentation of the' diametrically opposed ears I-I to the bending dies at the stations S1 and S2. The box next moves to the tapping Station Y where the ears are simultaneously tapped by the taps 91 of thev thread tapping machine 84. The box next moves to the grinder |05 at station Z where the edges of the Vside walls of the box are' brought into contact with the outer face of the grinding wheel |01 to remove rough burrs from the trimmed'edges of the box, and thus complete the making of an outlet box as shown in Figure 16. As previously explained, the finished box nally reaches' the stripper device which disconnects the box from'itscarrier unit.

While we have shown and described what we consider'to be the preferred embodiment of the invention for a combined automatic machine and specifically set forth the use of the same for the making of electric outlet boxes, it is to be understood that such changes in construction, design, proportions, and uses, may be resorted to if desired, and we do not wish to restrict ourselves to anything less than the whole of the invention as set forth in the claims hereto appended.

Having thus described the invention, what we Aclaim as new and desire to secure by Letters Patent of the United States, is:

, 1. In a combined automatic machine for use inthe making of metal outlet boxes, 'a plurality of metal box carrier units, each including a rotatable chuck for supporting a metal box to be worked upon, a row of work stations, means for intermittently moving said carrier units successively into alined positions relative to the respective, work stations, work'performing means located at the respective work stations for suci cessively trimming the edges of the side walls i worked upon, a row of suitablyspaced workstations. `means-fointermittently moving saidA car rier units successively into alined positions relative tothe respective Work stations, work performing means located at the respective work stations for successively trimming the edges of' the side walls of .metai boxes of surplus material and forming perforated cover attaching ears on opposed side walls thereof, punching knockouts successively in the respective side Walls of `the boxes,v and for successively returning `the punched knockouts, for-*bending the attaching ears at right angle to the respectiveside Walls on which' they are iormed, and for thread-tapping the perforated cover attachingears, and means for impartingsimultaneous partial rotation to the `chucks duringl each intermittent movement of the carrier units to successively present the, sidewalls.' of the-boxes to the respective work performing means.

3.1 In a machine tor', use in the makingxof metal outlet boxes,.a row of equidistantly spaced work stations to which a pre-shaped drawn metal box is presented fory successively trimming` the free edges of the side Walls ofr the same, successively punching knockouts in the respective side Walls of the box. and successively replacing the knock outs, tool means located at the respective work stations for performing the respective work functions assigned thereto, box carrier means for si multaneously, presenting boxes to the respective work stations for operation thereon by the tool means, said box carrier means including a plurality of carrierunitsl each carrier unit including a rotary chuck for supporting a box, means for intermittently moving the box carrier means a distance to cause the carrier units to move from one Work station to the next adjacent Work station, and means for turning the rotary chucks a predetermined degree of rotation during the movement of the box carrier units `between work stations for successively presenting the side walls of the metal boxes to the respective tool means.

4. In a machine for making metal outlet boxes, means for successively trimming the free edges of the side walls of the box and for shaping the cover attaching ears thereof, means for successively punchingknockouts in the respective side walls of the box, means for successively pressing the knockouts'to return them Within the side walls, means for bending the ears formed by the .n

trimming means, and box carrier means for successively presenting side Walls of the metal boxes to the aforementioned means in the order named.

5. `In a machine for making metal outlet boxes, means for successively trimming the free edges of the side Walls of .the box and for shaping the cover attaching ears thereof. means for successivebr punching knockouts in the respective' side walls of the box, means. for successively pressing theknockouts to return them within the side walls, means for bending the ears formed` by the trimming means at right angle to the side walls, ear thread tappingmeans, edge grinding means, and box carrier means for successively presenting the side walls of the metal boxes to the a-foree I.

mentioned means in the order named.

6. In a combined automatic machine for use in the making of metal outlet boxes, a pluralityv of metal box carrier units, each including ay rotatable chuck for supporting a metal box to be Worked upon, a row' of work stations, means for inter.- mittently moving said carrier units successively into alined positions relative to the respective work stations, box feeding means located in advance of the first work station of `said row of Work stations for feeding boxes to the carrier units during. intervals of rest between intermittent movements of the carrier units, work performing means located at the respective Work stations for successively trimming the edges of the side walls of metal boxes, punching knockouts successively in the respective side Walls of the boxes, and for successively returning the punched knookouts, and means for imparting simultaneous partial rotation to the; chucks during each intermittent movement of the carrier units to successively present the side Walls of the boxes to the respective work performing means.

'7. In a combined automatic machine for the making of outlet boxes as set forth in claim 6, including automatic means located beyond the last work station of the row of work stations for releasing the boxes from the carrier units.

8. In a machine for use in the making of metal outlet boxes, a row of equdistantly spaced work stations to which a pre-shaped drawn metal box is presented for successively trimming the free edges of the side walls of the same, successively punching knockouts in the respective side Walls of the box, and successively replacing the knockouts, tool means located 'at the respective work stations for performing the respective work functions assigned thereto, box carrier means for simultaneously presenting boxes to the respective Work stations for operation thereon bythe tool means, said box carrier means including a plurality` of carrier units, each carrier unit including a rotary chuck for supporting a box, means for intermittently moving the box carrier means a distance to cause the carrier unitsto move from one Work station to the next adjacent work station, automatic box feeding means located in ad Vance of the rst Work station of said row of work stations for feeding boxes to the rotary chucks of the carrier units, and means forV turning the rotary chucks a predetermined degree of rotation during the movement of the box carrier units be tween work stations for successively presenting the side walls of the metal boxes to the respective tool means.

9. In a machine for use in the making of metal outlet boxes as set forth in claim 8 including automatic means located beyond the last work station of the row of work stations for separating the boxes from the rotary chucks.

MABEL B. WALKER, TRUST COMPANY OF GEORGIA, By CARROLL PAYNE JONES,

Trust Ojccr, Exccutors `of the Estate of Ralph M. Walker,

Deceased.

GEORGE'` P. AIl}iI}ZL}iil\1iDIEIR` 

